EBCDIC (Extended Binary Coded Decimal Interchange Code) is an 8-bit character encoding created by IBM for its mainframe and midrange systems. It is still used on z/OS and IBM i platforms, which is why converting between EBCDIC and ASCII remains a common task in data migration.

Which EBCDIC code page does this use?

It uses Code Page 037, the US and Canada EBCDIC variant. EBCDIC has dozens of national code pages that differ mainly in the placement of currency symbols and a few punctuation marks, so results for those characters can vary by code page.

Why are EBCDIC letters not in a simple sequence?

In ASCII the letters A to Z occupy consecutive codes, but in EBCDIC they are split into blocks with gaps. The letters A to I, J to R, and S to Z each sit in separate ranges. This is a legacy of the punched-card column layout EBCDIC was designed around and is a classic source of sorting bugs.

What happens to characters not in the code page?

When encoding, any character with no Code Page 037 equivalent is skipped and listed below the output. When decoding, a byte that has no printable CP037 character is shown as a replacement marker so you can see exactly where it occurred.

Does the conversion happen on a server?

No. The full Code Page 037 table is built into the tool and all conversion runs locally in your browser. No text or byte data is uploaded.

What is the EBCDIC ↔ ASCII Converter?

Free EBCDIC to ASCII converter using IBM Code Page 037. Encode ASCII text to EBCDIC byte values in hex, decimal, or binary, and decode EBCDIC bytes back to readable text. Handles the non-contiguous EBCDIC letter layout. Runs entirely in your browser. It runs free in your browser on Gera Tools, with nothing uploaded.

EBCDIC ↔ ASCII Converter

Name: EBCDIC ↔ ASCII Converter
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

EBCDIC — the Extended Binary Coded Decimal Interchange Code — is IBM’s 8-bit character encoding for mainframe and midrange systems. It is completely unrelated to ASCII and assigns different byte values to every printable character. This converter translates between ASCII text and EBCDIC byte values using IBM Code Page 037, with output in hex, decimal, or binary.

How it works

The tool carries the full printable Code Page 037 mapping. Encoding looks up each character in the reverse table to find its EBCDIC byte value and formats that byte in your chosen base. Decoding parses each byte value you enter, validates it as 0–255, and maps it to its Code Page 037 character.

Characters outside Code Page 037 are handled explicitly — never silently dropped or invented. On encoding, unrepresentable characters are skipped and listed. On decoding, non-printable bytes are shown as replacement markers so you know exactly where they appear.

The non-contiguous letter layout

The single most surprising feature of EBCDIC is that its letters are split across three non-consecutive blocks:

Block	Capital letters	EBCDIC byte range
Block 1	A–I	0xC1–0xC9
Block 2	J–R	0xD1–0xD9
Block 3	S–Z	0xE2–0xE9

The gap bytes (0xCA–0xD0, 0xDA–0xE1) are unassigned or assigned to other characters, not to letters. This layout reflects EBCDIC’s origin in the IBM 026 keypunch card column layout, where physical card columns were arranged differently from a linear alphabet.

The practical consequence: a naïve byte-value sort of EBCDIC text does not produce alphabetical order. Any sort algorithm ported from ASCII to an EBCDIC system must use a proper collation sequence, not raw byte comparison — a well-known trap in mainframe data migration.

Code Page 037 — what it covers

Code Page 037 is the US and Canada variant of EBCDIC. It includes the standard Latin alphabet (upper and lower case), digits 0–9, common punctuation, and several special characters. Its currency symbol is the dollar sign. Other national EBCDIC code pages differ mainly in the placement of currency symbols, a few punctuation characters, and some special symbols. If you are working with data from a European IBM installation, Code Page 273 (German), 285 (UK), or 297 (French) may be needed instead.

Worked example

The ASCII text Hello, World! encodes in Code Page 037 to:

H    e    l    l    o    ,    ' '  W    o    r    l    d    !
C8   85   93   93   96   6B   40   E6   96   99   93   84   5A

Key values to recognise: space is always 40, digits 0–9 map to F0–F9, and upper-case letters are scattered across the C, D, and E ranges.

To decode, enter those hex bytes separated by spaces and the tool returns the original text. Everything runs locally in your browser — no text or byte data is uploaded.

When EBCDIC conversion is needed

Mainframe file exports: IBM z/OS and IBM i (AS/400) file transfers often arrive as raw EBCDIC bytes. Converting to ASCII is the first step before processing.
Data migration: Moving records from a mainframe database to a modern system requires character-by-character conversion, not just encoding header changes.
Debugging mainframe logs: Log files from z/OS Syslog, JES2 spool output, and DB2 EXPLAIN output use EBCDIC; converting lets you read them in a standard text editor.
Legacy COBOL interfaces: Some modern systems must format data as EBCDIC to interoperate with legacy COBOL applications still running on IBM hardware.